diff --git a/libc/Android.bp b/libc/Android.bp
index 3e607f6..01c0cad 100644
--- a/libc/Android.bp
+++ b/libc/Android.bp
@@ -760,6 +760,7 @@
                 "arch-arm/generic/bionic/strcpy.S",
                 "arch-arm/generic/bionic/strlen.c",
 
+                "arch-arm/bionic/__aeabi_read_tp.S",
                 "arch-arm/bionic/atomics_arm.c",
                 "arch-arm/bionic/__bionic_clone.S",
                 "arch-arm/bionic/_exit_with_stack_teardown.S",
diff --git a/libc/NOTICE b/libc/NOTICE
index 40a5704..120c4fd 100644
--- a/libc/NOTICE
+++ b/libc/NOTICE
@@ -1068,6 +1068,34 @@
 
 -------------------------------------------------------------------
 
+Copyright (C) 2019 The Android Open Source Project
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+ * Redistributions of source code must retain the above copyright
+   notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in
+   the documentation and/or other materials provided with the
+   distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGE.
+
+-------------------------------------------------------------------
+
 Copyright (c) 1980, 1983, 1988, 1993
    The Regents of the University of California.  All rights reserved.
 
diff --git a/libc/arch-arm/bionic/__aeabi_read_tp.S b/libc/arch-arm/bionic/__aeabi_read_tp.S
new file mode 100644
index 0000000..f6f9757
--- /dev/null
+++ b/libc/arch-arm/bionic/__aeabi_read_tp.S
@@ -0,0 +1,48 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <private/bionic_asm.h>
+
+// For arm32 and -mtp=soft, the compiler uses this function to read the thread
+// pointer for ELF TLS accesses. With -mtp=cp15, the compiler inlines the call
+// instead. GCC defaults to -mtp=auto, which inlines this function with
+// -march=armv7-a. Clang does not yet implement -mtp=auto, and instead defaults
+// to -mtp=soft.
+//  - https://bugs.llvm.org/show_bug.cgi?id=38394.
+//  - https://reviews.llvm.org/D34878?id=114573.
+//
+// This function must preserve every register except r0, ip, lr, and cpsr.
+//
+// See "Run-time ABI for the ARM Architecture"
+// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf
+//
+ENTRY(__aeabi_read_tp)
+  // __get_tls()
+  mrc p15, 0, r0, c13, c0, 3
+  bx lr
+END(__aeabi_read_tp)
diff --git a/libc/bionic/pthread_create.cpp b/libc/bionic/pthread_create.cpp
index 8e8d180..06d2ecb 100644
--- a/libc/bionic/pthread_create.cpp
+++ b/libc/bionic/pthread_create.cpp
@@ -76,8 +76,6 @@
     return nullptr;
   }
 
-  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, allocation, allocation_size, "bionic TLS guard");
-
   // Carve out the writable TLS section.
   bionic_tls* result = reinterpret_cast<bionic_tls*>(static_cast<char*>(allocation) +
                                                      PTHREAD_GUARD_SIZE);
@@ -88,7 +86,6 @@
     return nullptr;
   }
 
-  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, result, BIONIC_TLS_SIZE, "bionic TLS");
   return result;
 }
 
@@ -111,7 +108,6 @@
     // We can only use const static allocated string for mapped region name, as Android kernel
     // uses the string pointer directly when dumping /proc/pid/maps.
     prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ss.ss_sp, ss.ss_size, "thread signal stack");
-    prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, stack_base, PTHREAD_GUARD_SIZE, "thread signal stack guard");
   }
 }
 
@@ -214,8 +210,6 @@
     munmap(space, mmap_size);
     return nullptr;
   }
-  prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, space, stack_guard_size, "thread stack guard");
-
   return space;
 }
 
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 4b8463f..f78014d 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1446,6 +1446,7 @@
 
 LIBC_Q { # introduced=Q
   global:
+    __aeabi_read_tp; # arm
     __res_randomid;
     android_fdsan_close_with_tag;
     android_fdsan_create_owner_tag;
diff --git a/libc/tzcode/bionic.cpp b/libc/tzcode/bionic.cpp
index cb9c359..9051308 100644
--- a/libc/tzcode/bionic.cpp
+++ b/libc/tzcode/bionic.cpp
@@ -228,13 +228,18 @@
   if (fd >= 0) return fd;
 #else
   // On the host, we don't expect those locations to exist, and we're not
-  // worried about security so we trust $ANDROID_DATA and $ANDROID_ROOT to
-  // point us in the right direction.
+  // worried about security so we trust $ANDROID_DATA, $ANDROID_RUNTIME_ROOT
+  // and $ANDROID_ROOT to point us in the right direction.
   char* path = make_path("ANDROID_DATA", "/misc/zoneinfo/current/tzdata");
   fd = __bionic_open_tzdata_path(path, olson_id, entry_length);
   free(path);
   if (fd >= 0) return fd;
 
+  path = make_path("ANDROID_RUNTIME_ROOT", "/etc/tz/tzdata");
+  fd = __bionic_open_tzdata_path(path, olson_id, entry_length);
+  free(path);
+  if (fd >= 0) return fd;
+
   path = make_path("ANDROID_ROOT", "/usr/share/zoneinfo/tzdata");
   fd = __bionic_open_tzdata_path(path, olson_id, entry_length);
   free(path);
diff --git a/tests/Android.bp b/tests/Android.bp
index 899fc66..7d56a22 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -64,6 +64,7 @@
     name: "libBionicStandardTests",
     defaults: ["bionic_tests_defaults"],
     srcs: [
+        "__aeabi_read_tp_test.cpp",
         "alloca_test.cpp",
         "android_get_device_api_level.cpp",
         "arpa_inet_test.cpp",
diff --git a/tests/__aeabi_read_tp_test.cpp b/tests/__aeabi_read_tp_test.cpp
new file mode 100644
index 0000000..ab96af9
--- /dev/null
+++ b/tests/__aeabi_read_tp_test.cpp
@@ -0,0 +1,38 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <gtest/gtest.h>
+
+#include "private/__get_tls.h"
+
+#if defined(__arm__)
+extern "C" void* __aeabi_read_tp();
+TEST(aeabi, read_tp) {
+  ASSERT_EQ(__aeabi_read_tp(), static_cast<void*>(__get_tls()));
+}
+#endif